Make 1 copy of the blackline master for each group of 2 students, plus a few extras. Place two copies of uncut blackline masters in envelopes to serve as answer keys. Cut the remaining copies blackline master for students to use. Discard the cut slips that say “The above diagram also matches this sentence.” Consider using a different color of paper for each group's copy of the blackline master so that misplaced slips can quickly be put back.